re: 'calling yourself'....
reminds me of when BELL here installed 'call forwarding'...
2 stories...
1st. Just after BELL had it 'up and running' ,a guy in Hamilton call forwards his home number to his Toronto business number, then goes to work....just before leaving the office he call forwards his office number to his home number. Some time later, someone called one of his numbers. Couple hours later the entire 'trunk' system from Hamilton to Toronto shuts down ! Seems the Bell 'engineers' never ,ever thought about a 'sunset loop'. Call come to the home number get forwarded to his office, that call gets forwarded to his home, which gets forwarded to his office,each time taking up a pair of wires between Hamilton and Toronto. Eventually all the lines are used and the system crashed. Adding a couple lines of code fixed THAT problem.
2nd. Bell decide to upgrade their 'computer' here in Hamilton,on a Sunday and erased ALL the call forwarding in use at the time. Kinda wondered why I hadn't had any business calls, hmmm. I call Bell, thay say 'just enter the call forward on my phone'. I say 'I don't have access to my phone', it's SUNDAY and the building is locked, they say'welll in that case, we'll have to disconnect your service sine we(Bell) can't access it for service. My response was ' patch me to the 870 corordinator, and 30 seconds later my call forwarding was working.